Bath tub



FIG. 1 is a perspective view of a bath tub showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side elevation view thereof, the left being substantially a mirror image of that shown; and

FIGS. 4 and 5 are right and left end elevation views thereof, respectively. 

The ornamental design for a bath tub, as shown and described. 